Determination of 11 priority pollutant phenols in wastewater using dispersive liquid-liquid microextraction followed by high-performance liquid chromatography-diode-array detection.

Dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography-diode-array detection was applied for the extraction and determination of 11 priority pollutant phenols in wastewater samples. The analytes were extracted from a 5-mL sample solution using a mixture of carbon disulfide as the extraction solvent and acetone as the dispersive solvent. After extraction, solvent exchange was carried out by evaporating the solvent and then reconstituting the residue in a mixture of methanol-water (30:70). The influences of different experimental dispersive liquid-liquid microextraction parameters such as extraction solvent type, dispersive solvent type, extraction and dispersive solvent volume, salt addition, and pH were studied. Under optimal conditions, namely pH 2, 165-microL extraction solvent volume, 2.50-mL dispersive solvent volume, and no salt addition, enrichment factors and limits of detection ranged over 30-373 and 0.01-1.3 microg/L, respectively. The relative standard deviation for spiked wastewater samples at 10 microg/L of each phenol ranged between 4.3 and 19.3% (n = 5). The relative recovery for wastewater samples at a spiked level of 10 microg/L varied from 65.5 to 108.3%.